The present invention relates to a device, made of polymeric material, for supporting and positioning a vehicle stabilizing bar, and a vehicle stabilizing system comprising such a device.
Stabilizing bars are widely used as elastic components of vehicle suspensions, and substantially provide for elastically connecting the two suspensions of the same vehicle axle to increase the roll rigidity of the suspensions and improve passenger comfort and the road-holding capacity of the vehicle.
A stabilizing bar normally comprises a steel rod substantially parallel to and a given distance from the wheel axle for stabilizing, and having two end arms bent towards the axle and connected to the suspension members by means, say, of connecting rods; and the bar is normally fitted to the vehicle frame by means of two supports along the straight portion of the bar between the end arms.
Supports are known comprising rubber or rubber-metal bushes, and which are fitted by metal connecting brackets to the vehicle body. Besides being relatively heavy by comprising metal components, this type of support does not normally allow the bar to rotate or slide axially inside the support itself, on account of the compressed rubber adhering tightly to the bar.
The best stabilizing results are known to be achieved when the bar is simply twisted and induces no undesired stress on the supports secured to the vehicle frame, while at the same time providing for rapid response at the passenger compartment. In the case of the supports described above, the rubber bushes form an elastic chain defined not only by the steel from which the bar is made, but also by the rubber of the supports, thus increasing the elasticity and impairing the response of the stabilizing system.
By way of a solution, stabilizing systems have been devised in which the bar is connected to the vehicle by supports comprising antifriction sleeves, and which, when twisted, therefore allow the bar to rotate freely with respect to the elastic sleeve, without the sleeve in turn being twisted. Besides being heavy, systems of this sort, however, pose the problem of how to maintain the transverse position of the bar, which the sleeves allow not only to rotate freely, but also to translate with respect to the supports.
One known solution to the problem provides for bending the bar close to the supports so as to form axial-stop elbows. Such a solution, however, subjects the bar to considerable bending stress, which impairs the stabilizing efficiency and response of the bar. In another known solution, the bar is fitted, close to the supports, with axial-stop members made separately and comprising, for example, projections engaging respective seats on the bar. Though effective, this solution involves assembly and cost problems on account of the large number of separate components employed.